Optimizing combination of liver-enriched transcription factors and nuclear receptors simultaneously favors ammonia and drug metabolism in liver cells
Optimizing combination of liver-enriched transcription factors and nuclear receptors simultaneously favors ammonia and drug metabolism in liver cells
复制标题
肝脏富集的转录因子和核受体的优化组合同时有利于肝细胞中的氨和药物代谢
DOI：
10.1016/j.yexcr.2017.12.015
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发表时间：
2018
影响因子：
3.7
通讯作者：
Nanhong Tang
中科院分区：
文献类型：
--
作者：
Yongfa Su;Zhanfei Chen;Linlin Yan;Fen Lian;Jianhua You;Xiaoqian Wang;Nanhong Tang
HepG2细胞系因其永生化而被广泛应用于肝脏疾病的研究，但其尿素合成关键酶和细胞色素P450(Cytochromes P450，Cyps)的低表达限制了其临床应用。在前期工作的基础上，我们研究了精氨酸酶1(Arg1)和鸟氨酸转氨甲基酶(OTC)在HepG2细胞中的转录调控。我们还筛选了肝脏浓缩转录因子(LETF)和异种核受体的最佳组合，以促进关键的尿素合成酶和五种主要细胞周期蛋白在HepG2细胞中的表达。从而建立了重组人肝癌细胞株HepG2。结果表明，C/eBPβ而不是C/eBPα可上调Arg1和Pgc1α的表达，而HNF4α则协同调节Otc的表达。筛选出C/EBpβ+HNF4α+HNF6+PXR和C/EBPβ+HNF4α+HNF6+CAR两个最佳组合。与对照细胞相比，经两种优化组合修饰的重组HepG2细胞氨代谢增强，细胞色素P450酶活性增强。此外，Hep G2/(C/EBpβ+HNF4α+HNF6+PXR)细胞对氨的还原作用比本研究中测试的任何其他组合都要强。本工作表明，优化转录因子组合将同时促进肝细胞氨代谢和药物代谢。该优化组合构建的重组HepG2肝细胞系为生物人工肝的应用和药物毒性检测提供了一种改进的替代手段。
The HepG2 cell line is widely used in studying liver diseases because of its immortalization, but its clinical application is limited by its low expression of the urea synthesis key enzymes and cytochromes P450 (CYPs). On the basis of our previous work, we investigated the transcriptional regulation of arginase 1 (Arg1) and ornithine transcarbamylase (OTC) in HepG2 cells. We also screened for the optimal combination of liver enrichment transcription factors (LETFs) and xenobiotic nuclear receptors that can promote the expression of key urea synthases and five major CYPs in HepG2 cells. Thus, recombinant HepG2 cells were established. Results showed that C/EBPβ, not C/EBPα, could upregulate expression of Arg1 and PGC1α and HNF4α cooperatively regulate the expression of OTC. The two optimal combinations C/EBPβ+HNF4α+HNF6+PXR and C/EBPβ+HNF4α+HNF6+CAR were selected. Compared with the control cells, the recombinant HepG2 cells modified by the two optimal combinations exhibited enhanced ammonia metabolism and CYP enzyme activity. Moreover, the HepG2/(C/EBPβ+HNF4α+HNF6+PXR) cells more strongly reduced ammonia than any other combination tested in this study. The present work indicated that optimizing the combination of transcription factors will simultaneously promote hepatocyte ammonia metabolism and drug metabolism. The recombinant HepG2 liver cell line constructed by the optimal combination provided an improved alternative means for bioartificial liver applications and drug toxicity testing.